Choice electric motor For a boat today is no longer the lot of exclusively quiet hunting for pike in forbidden areas or fishing in protected water bodies. Modern technology has allowed us to create power units that can not only sneak up silently to the trophy, but also confidently lead the vessel against the wind and current, acting as a full-fledged alternative to gasoline analogues of low power.
However, to avoid disappointment in the purchase, you need to clearly understand the difference between marketing promises and real technical specifications. A mistake in the calculations can lead to the fact that your boat will barely crawl, and the battery will run out in an hour, leaving you drifting in the middle of the reservoir.
In this article, we'll look at everything from calculating the thrust required to choosing the type of control and battery capacity. maximum speed - not the main parameter, and what really should be paid attention when completing your boat.
Calculating traction and power: The mathematics of your calmness
The most common mistake of beginners is to choose the engine solely by the length of the vessel or its appearance. traction Thrust, measured in pounds, not horsepower, is the number that determines whether a motor can move the boat and keep its course.
There's a proven formula for calculating the minimum thrust required, which takes into account displacement and operating conditions. If you plan to fish in calm water without flow, you can use a base coefficient, but for large bodies of water with wind and flow, there is not much power.
⚠️ Attention: Never use a sideways motor for the intended thrust. The engine running at 100% power causes windings to overheat and reduce efficiency, which reduces battery life.
Let's look at the approximate thrust values based on the type and size of the boat, and the averages are because the shape of the hull and the presence of wind make adjustments.
| Boat type/Long length | Approximate displacement | Recommended traction (lbs) | Max. speed (km/h) |
|---|---|---|---|
| Inflatable boat (up to 3.2 m) | 400 kg | 30 - 34 lbs | 5 - 7 |
| PVC or Aluminum (3.2 - 3.8 m) | 400 - 700 kg | 40 - 45 lbs | 7 - 9 |
| Boat / Large Boat (up to 5 m) | 1200 kg | 55 - 70 lbs | 9 - 12 |
| Heavy boat (over 5 m) | more than 1,200 kg | 80+ lbs | 10 - 14 |
When choosing, it is important to consider that electric It's linear only up to a point. Once it reaches peak load, efficiency drops, so for a 3.5-meter boat with full gear and two fishermen, it's more sensible to take a 45-50-pound engine than the base 35-pound option.
Types of lower unit and methods of installation on board
The design of the lower part of the motor, or lower unitThere are several basic types, each of which is tailored to suit its own purposes, and for fishing in grassy bays or shallow waters, the design of the screw steering system is critical.
Classic two-blade propellers provide good speed on clean water, but often "catch" grass by winding it on a shaft. This leads to a boat stop and the need to clean. turbine or multi-bladed screws with increased compression are better at coping with algae, although they can be a little noisier.
As for the installation, the choice depends on the material of the boat and the frequency of use:
- 🛶 Tran mounting: It's a versatile option for PVC, aluminum and plastic, and it's mounted on the rear side with rods, and the key is to make sure that the transom can withstand the weight of the battery and the motor.
- ⚓ Nasal anchorage: It is commonly used on large boats and boats for precise positioning (trolling) and requires a special platform to be placed on the nose.
- 🔩 Fixing to the john: A specific variant for some models of inflatable boats, where the engine is hidden in a special compartment, leaving only the screw open.
It's important to remember lower unitToo short a leg will lead to the propeller sucking air (cavitation) and loss of traction, especially on the wave. Too long a leg will create excess water resistance. The optimal position is when the propeller is submerged 15-20 cm below the keel.
What is cavitation and why is it dangerous?
Cavitation is the formation of vapor bubbles in the fluid stream caused by local pressure drops. For a outboard motor, this means that the screw starts spinning in the air bubbles, losing traction to the water. This not only reduces speed, but also causes erosion of the propeller blades and vibrations that can damage lower unit.
Control: a romple, pedal or GPS anchor?
Control ergonomics is what defines comfort during hours of fishing. The market offers three main types of management, and the choice here depends on the style of your fishing. If you like active search and frequent change of positions, one type will be more convenient, if you prefer methodical trolling - the other.
The most common option is pump-control. The handle of the hummel not only allows you to set direction, but also to adjust speed, a classic that anyone who has a outboard motor can understand, but holding the rummel with one hand limits your ability to handle the gear.
For those who want complete freedom of hand, there is a foot-controlThe pedal allows you to adjust your course with your toe, leaving your hands free for spinning, and it's an ideal choice for trolling in large bodies of water where you need constant course adjustment.
The top of evolution was the system with GPS anchor (i-Pilot, Ghost Control, and analogues) You set a dot on a map, and the motor holds the boat in that coordinate, making up for the wind and current demolition, and it's complex electronics that require calibration, but it's worth it.
⚠️ Attention: GPS control systems require the installation of an external GPS antenna (usually on the bow of a boat) and the calibration of the compass away from metal objects and magnetic fields, otherwise the anchor can carry the boat away.
It is also worth mentioning. wirelessThey allow you to control the engine from anywhere in the boat, which is convenient when catching fish or mounting gear, but you should not rely on them alone: always have a backup method of control (a tiller or a pedal).
When using foot control, be sure to fix the pedal with a seat belt or a special platform so that when a sharp jerk of the fish, the leg does not slip and change the course of the boat to a dangerous one.
Power: battery selection and timing calculation
The heart of your electrical system is batteryIt's a performance that determines how long you're going to be on the water, and for boat electric motors, conventional car starter batteries designed for short-term high-current returns are absolutely not suitable.
You need Deep Cycles, which can deliver low-current power for long periods of time and can withstand many charge-discharge cycles, and today the choice is between two main technologies: lead-acid (AGM/GEL) and lithium-iron-phosphate (LiFePO4).
Lead batteries are cheaper but heavier and have a lower cycle life. Lithium (LiFePO4) is much lighter (weight can be 2-3 times less at the same capacity), have almost 100% discharge depth and last 5-10 times longer, but their initial cost is higher.
To calculate the approximate operating time, use a simple formula that takes into account the battery capacity and the current consumed by the motor. The current of consumption depends on the speed: at a minimum, the motor can take 5-10 Amps, and at full speed - 40-50 Amps or more.
☑️ Check before purchasing AKB
Low-power motors run from 12 volts. Medium-power motors (55 lbs and above) often require 24 or 36 volts, which means connecting two or three batteries in series, respectively, which complicates the system but increases efficiency.
Protection and durability in an aggressive environment
Water, especially salt water, and constant vibration are the main enemies of electronics. Therefore, when choosing a motor, special attention should be paid to the quality of materials and protection. The body of the motor must be made of composite materials or treated with special anti-corrosion compounds.
The key element is lower unit. Good models have stainless steel or reinforced composites, and it's also important to have tightness, and even if the engine doesn't sink completely, splashes and condensate do their job.
Please note the following protective functions:
- 🛡️ Thermal protection: Automatic shutdown when the windings or controller overheat.
- 🔌 Protection against short circuit: Critical when using homemade cables or bad contacts.
- 🌊 Water resistance of the control board: IP67 and above allow the motor to survive even if it is fully submerged.
Don't forget about the mechanical protection. pin-spin Or the friction on the screw will save the gearbox from breaking when hitting a hard obstacle (stone, snag), in cheap models of this protection may not be, and the gears of the gearbox will have to be hit.
The composite leg of the motor is not only lighter than the metal leg, but also does not create magnetic interference, which is critical for the correct operation of the compass in systems with a GPS anchor.
Frequent questions and final recommendations
So to sum up, choosing an electric motor is about balancing budget, weight and comfort, not chasing the fastest speed if you want to go fishing, but reliability, quiet driving and long water stays.
When buying, be sure to check the equipment: often the cables of the right length or fasteners have to be purchased separately, and remember that a quality battery is 50% of the success of the entire system.
Can an electric motor replace a gasoline engine?
The electric motor can completely replace the gasoline engine only if your routes do not exceed 20-30 km per day and speed is not a priority. For long-distance crossings and planing heavy boats, gasoline is not yet competitive, but the electric motor is ideal as a second, "quiet" engine.
How to store the battery in winter?
Lead batteries should be stored in a fully charged state at 0... + 10 ° C, periodically (once a month) recharged. Lithium (LiFePO4) is better stored charged by 50-70% at room temperature, they are less sensitive to temperature, but frost below -20 ° C is also undesirable for them.
Do I need to lubricate the electric motor?
Yes, but only certain knots, regular lubrication requires gear gear gear gear (oil changes are scheduled, usually once a season) and movable parts of the lift/rotation mechanism.
Can an electric motor be used in salt water?
You can, but only if the model is marked "Saltwater" or "SW"; such engines have enhanced corrosion protection (anodes, special coatings), after each outing to sea, the engine must be washed with fresh water.